Control of bacterial wilt of growing peanut

1. Symptoms. The disease of peanut bacterial wilt began to occur before and after flowering, but the disease was the most serious at the stage of flowering and needling, and the disease was alleviated after podding. The characteristics of the greatest symptoms are as follows: the upper leaves of the diseased plant withered rapidly, the vascular bundles of the underground roots turned brown, the longitudinal rhizomes, and turbid bacterial pus could be exudated from the squeezed incision when it was moist. If the section of the rhizome disease was suspended and immersed in clean water, it can be seen that smoke-like turbid fluid gushed out from the incision, which is a reliable basis for the diagnosis of the disease. Usually the chlorophyll of the withered leaves has not been destroyed, although the leaves are not shiny, they are still green, hence the name bacterial wilt.

2. The regularity of the disease. The pathogenic bacteria of bacterial wilt overwintered mainly in soil, but also in diseased remains and soil fertilizer. Diseased soil and diseased fertilizer were the main sources of primary infection of the disease in the following year. Bacteria spread through soil, Rain Water, irrigation water, agricultural activities and so on, and invaded from the host rhizome wound or natural orifice. The occurrence and prevalence of the disease is closely related to weather, soil, farming system, plant growth period, variety resistance and other factors. High temperature and heavy rain, especially when it is sunny and rainy, or prolonged drought and sudden rain, and sharp changes in soil temperature and humidity are the most likely to induce the disease; the coarse sand with shallow soil layer and poor water and fertility conservation or yellow clay with poor permeability are favorable for the disease; the disease in continuous cropping land is more serious than that in rotation land; it is easy to occur when nitrogen fertilizer is applied in continuous cropping land; trailing type varieties are more resistant than direct type and pearl bean type varieties; southern type varieties are more resistant than northern type varieties. The incidence from pre-flowering to podding stage accounted for more than 70% of the incidence during the whole growth period.

3. Control measures ⑴ reasonable rotation. It is best to implement flood-drought rotation, at least with sugarcane, sweet potato and other dry land rotation. The number of years of crop rotation depends on the severity of the disease. Resistant varieties were selected for ⑵. Xie Kangqing 10, 11, Tianfu 11, Yuhua 14, Yuanza 9102, Yueyou 589,320, Guiyou 28, Quanhua 3121, Taishan Pearl Dou can be selected according to local conditions. ⑶ strengthens cultivation management. Turn the soil deeply in the sun or divert water to soak the field (the longer the time is, the better); regulate the drainage and irrigation system, improve the ability of preventing waterlogging and drought resistance, prevent series irrigation, properly increase lime, adjust soil acidity, remove central diseased plants in time, and pay attention to field hygiene; formula fertilization, avoid partial application of nitrogen fertilizer, do not apply soil fertilizer with diseased residues. ⑷ adopted the method of picking and treating by spraying liquid to block the disease center. 20% quinolinone 1000 times solution, or potassium permanganate solution or copper ammonia solution can be used to spray gonorrhea points and adjacent healthy plants for 2-3 times or more times, which plays a certain role in blocking the disease center and controlling the spread of the disease.